Treatment element for an appliance for cleaning dental interstices, a method and device for the production thereof

ABSTRACT

The invention relates to a treatment element ( 1 ), which can be mounted onto an appliance for cleaning dental interstices. Said element comprises a shank ( 2 ), provided with bristles that radiate outwards ( 3 ). The brush head has a substantially polygonal, in particular triangular form ( 5 ). Said head can have a series of zones of different diameters along the shaft ( 2 ) and in particular, tapers ( 6 ) towards its end.

The invention relates to a treatment element for an appliance for cleaning dental interstices, which treatment element can be mounted on such an appliance and comprises a shaft from which bristles project radially, to a method for the production thereof and to a device suitable therefor.

Such a treatment element for an appliance for cleaning dental interstices is described in CH-688.261. This appliance is formed from a housing, a handle and a head which carries a holder for accommodating treatment elements.

The teeth are then cleaned by a movement of the treatment element, this movement being transmitted via an electric motor drive in the housing and via an eccentric shaft running in the handle.

A known treatment element in the form of a brush head is shown, for example, in the figures of CH-688.261 and has a conical shape in the direction of its longitudinal axis. The conical shape is readily suitable for being inserted into dental interstices, since the effective diameter of the treatment element increases the further the latter is inserted.

The object of the present invention is to provide a treatment element which works more effectively than treatment elements such as brush heads from the prior art.

This object is achieved according to the invention in that the treatment element is a brush head having an essentially triangular shape in cross section.

In this case, the expression “triangular shape” means that the ends of the bristles which are fastened to a central shaft form a triangle in the said cross-sectional view and not merely that bristles project from the central shaft in three directions at a distance of 120°.

A method of producing a treatment element is characterized by the features of claim 7.

A device for producing a treatment element is characterized by the features of claim 8.

Further advantageous configurations are described in the subclaims.

The invention will now be described in more detail with reference to the attached drawings, in which:

FIG. 1 shows a schematic cross section through a treatment element or brush head according to the invention,

FIG. 2 shows a schematic representation of a second exemplary embodiment of a treatment element having a brush head increasing in its diameter,

FIG. 3 shows a schematic cross section through a treatment element or brush head according to a third exemplary embodiment of the invention,

FIG. 4 shows a schematic representation, exaggerated in the curvatures, of a treatment element according to a fourth exemplary embodiment,

FIG. 5 shows a schematic perspective view of a further brush head according to the invention, and

FIG. 6 shows a sequence of cross-sectional views and side views of various further exemplary embodiments of treatment elements having a brush head varying in diameter.

FIG. 1 shows a treatment element or brush head 1 with a central shaft 2 to which a multiplicity of bristles 3 are fastened. Of these bristles 3, only a few are shown for the sake of clarity. Adjacent bristles 3, starting from the shaft 2, run in a slightly diverging manner and, starting from the shortest bristles provided with the reference numeral 13, in each case have a longer length until they are at the greatest distance from one another at the bristles 23, which are at an angle of 120° from one another. The material from which the bristles are made may be selected from the group of all the products accordingly used for toothbrushes, toothpicks and other cleaning materials.

The bristle tips 4 form a plane or, in the cross section of FIG. 1, an outer contour 5 of the treatment element 1, this outer contour 5 being rectilinear in a first approximation. An equilateral triangle is thus formed for the outer contour of the treatment element 1 according to FIG. 1. In a preferred production method, the outer contour 5, in a more precise representation, is in each case a slightly concave curve which ends in the corners of the triangle at the longest bristles. This can be seen in FIG. 4.

FIG. 2 shows a bristle configuration with bristles becoming longer along the shaft 2, which means only that the triangle 5 spread out by the bristles in cross section widens to form a triangle 15 having longer legs. The widening in this case is predetermined in the direction for fastening the treatment element to the brush head in order to form a tapering tip of the treatment element, it being possible for this tapering tip to be inserted into dental interstices in a simpler manner. In the present exemplary embodiment, the triangles 5 and 15 are equilateral. The connecting line between the respectively longest bristles 23, 33 is identified by the reference numeral 6. It is also possible for the curve 6 not to be a straight line but to run in a bent manner and/or for the curve 6, after a maximum having longest bristles 33, to merge again into shorter longest bristles 23. The shortest bristles 13 are also lengthened to form bristles 43.

FIG. 3 shows a third exemplary embodiment in which an acute-angled isosceles triangle is formed by the curves of the bristle tips. In this case, two sides 5 are the same length and a third side 25, the base line, is shorter. On two sides, the shortest bristles 13 are the same length; on the third side, the shortest bristles 53 are longer compared with the other shortest bristles 13. The shape of the brush head according to FIG. 3 is especially suitable for dental interstices. However, the acute angle may also be selected to be larger or smaller and may also become obtuse beyond a right angle.

Brush heads according to the above-mentioned exemplary embodiments are produced with a milling cutter, which is preferably located in a fixed position and in the case of which the brush heads (in the equilateral case) are each rotated about their shafts 2 by precisely 120°. The large diameter of the milling tool 40 results in the essentially straight side faces 35 of the triangle. However, in FIG. 4, in a schematic representation exaggerated in the curvatures, these straight lines are slightly concave side faces 35, in which case, by the selection of the milling cutter, the manufacturer has to strike a balance here between the speed of production of the treatment element and the quality of the side faces, since the bristles are cut obliquely in the corner regions.

It is likewise possible for the treatment element to have another outer contour, such as a hexagon or an octagon for example, instead of a triangle.

The method of producing a treatment element starts with a blank which has bristles of essentially the same length projecting radially from a shaft. The latter is fixed in a rotatable mounting. A milling tool is provided which is rotatable about an axis which runs parallel to the said rotatable mounting of the blank.

If the blank is now fixed in a first position, the axis of the milling tool is arranged at a distance from the blank, so that the milling tool produces essentially a first straight milled edge in cross section. The blank is then rotated in the rotatable mounting by a predetermined angle into a second position, the milling tool now producing a second essentially straight milled edge in cross section, so that the two milled edges enclose an angle of 180 degrees with one another minus the predetermined angle. The blank is then rotated in the rotatable mounting by in each case further predetermined angles (a second time in the case of the triangle, four times in the case of a hexagon) into further positions in order to produce a further straight milled edge by the milling tool until the last straight milled edge forms a predetermined angle with the first straight milled edge. The finish-machined blank can then be ejected.

A device for producing a treatment element accordingly has a first mounting for accommodating a blank and has a milling tool arranged parallel to the first mounting. The blank can be fixed in the first mounting and can be rotationally indexed by predetermined angles. The milling tool, initially and after each rotation, by rotation about its axis, can produce an essentially straight cut edge of the bristle tips of the blank in cross section until the treatment element has been produced with sections, adjacent to one another in cross section, of straight cut edges.

Another configuration, which is not shown in FIG. 1, uses two controlled shafts, one for the mounting of the brush and the other for the movement of the milling cutter. In particular, it is possible to activate a rotating milling cutter via an eccentric or a cam plate with regard to its distance from a rotating mounting for the brush, in which case the rotation of the eccentric may be a function of the rotation of the milling cutter or of the brush. Of course, the axis of the brush may also be adjusted via an eccentric disc relative to the axis of the milling cutter.

FIG. 5 shows a schematic perspective view of a further brush head. The twisted shaft 2, from which the bristles 3 project radially with the same convolution, can be readily seen. The bristles 3, following the curve 6, accordingly become shorter and shorter in order to then end together with the shaft 2.

Finally, FIG. 6 shows a sequence of cross-sectional views and side views of various further exemplary embodiments of treatment elements having a brush head varying in diameter. These brush heads are provided with the reference numerals 71, 72, 73, 74, 75, 76, 77, 78 and 79.

Brush head 71 is triangular in cross section and is constant in diameter over its length except for a tapering end section 81. Brush head 72, in cross section, is formed by two intersecting surfaces of revolution and is concave 82 at two opposite sides. It is of convex configuration in length.

Brush head 73 tapers towards the end of the shaft 2, and in this case the cross section is truncated 83 at the top in cross section. Brush head 74 tapers towards the end of the shaft 2 in a serrated shape 84, and in this case the cross section is a triangle having barrel-shaped side faces. Brush head 75 is similar to brush head 74 with regard to the side view, since here the taper towards the end of the shaft 2 runs in a wavelike manner in a plurality of steps, and the cross section in this case is essentially ovaloid 85.

Brush head 76 is designed with a saw-tooth curve 86 in the direction of the shaft 2, and in this case the cross section is a triangle having truncated corners 83 similar to brush head 73. Brush head 77 is designed with complementary sinusoidal curves 87 in the direction of the shaft 2, and in this case the cross section is a triangle similar to brush head 74.

Brush head 78 is designed to be tapered in the direction of the shank 2 like brush head 73, but in this case the cross section is a triangle having two barrel-shaped sides and one concave side 88. Finally, brush head 76 is designed in a saw-tooth shape in the direction of the shank 2 like brush head 76, but in this case the cross section is a rectangle 89 having four concave sides, and in addition the cut edge of the bristles above the axis shown is shorter than below the axis shown, i.e. the bristle lengths are asymmetrical. 

1. Treatment element (1) for an appliance for cleaning dental interstices, which treatment element (1) can be mounted on such an appliance and comprises a shaft (2) from which bristles (3, 13, 23, . . . , 63) project radially, characterized in that the treatment element (1) is a brush head having an essentially polygonal shape in cross section.
 2. Treatment element according to claim 1, characterized in that the cross section is essentially a triangle.
 3. Treatment element according to claim 2, characterized in that the longest bristles (23) in each cross section are in each case essentially the same length, so that the triangular shape is an equilateral triangle.
 4. Treatment element according to claim 2, characterized in that the triangle forms an isosceles triangle having an angle of less than 60 degrees opposite the base line.
 5. Treatment element according to claim 1, characterized in that the connecting line (6) of the longest bristles (23, 33), in the longitudinal direction of the shaft (2), runs at different radial distances from the latter (2) and/or in that the side lines (35) of the treatment element (1), in cross section, are arched concavely towards the shaft (2).
 6. Treatment element according to claim 1, characterized in that the connecting line (6) of the longest bristles (23, 33), in the longitudinal direction of the shaft (2), run at periodically different radial distances from the latter (2).
 7. A method for producing a polygonal treatment element, said method comprising the steps of: fixing a blank in a mounting rotatable about a first axis, the blank having bristles of substantially equal length extending radially from the first axis; providing a milling tool rotatable about a second axis extending parallel to the first axis; fixing the blank in a first position; arranging the second axis at a distance from the blank; milling a first straight edge of the bristles in cross-section by the milling tool; rotating the blank a predetermined angle about the first axis to a second position; milling a second straight edge of the bristles in cross-section by the milling tool such that the first straight edge and the second straight edge enclose 180 degrees minus the predetermined angle about the first axis; rotating the blank the predetermined angle about the first axis to a third position; milling a third straight edge of the bristles in cross-section by the milling tool such that the second straight edge and the third straight edge enclose 180 degrees minus the predetermined angle about the first axis; eventually repeating said rotating and milling steps until a last straight edge forms the predetermined angle with the first straight edge; and then ejecting the blank from the milling tool.
 8. Device for producing a treatment element according to claim 7, characterized in that it has a first mounting for accommodating a blank and has a milling tool arranged parallel to the first mounting, in which case the blank can be fixed in the first mounting and can be rotationally indexed by predetermined angles, and in that, with the milling tool, initially and after each rotation, by rotation about its axis, an essentially straight cut edge of the bristle tips of the blank can be produced in cross section until the treatment element has been produced with sections, adjacent to one another in cross section, of straight cut edges.
 9. A method for producing a treatment element, said method comprising the steps of: fixing a blank in a mounting rotatable about a first axis, the blank having bristles of substantially equal length extending radially from the first axis such that outer ends of the bristles form a cylindrical outer contour; providing a milling tool rotatable about a second axis extending parallel to the first axis; arranging the blank at a radial distance from the second axis of the milling tool such that a cutting surface of the milling tool contacts the cylindrical outer contour, the radial distance defining a first machining position of the blank; varying the radial distance between the blank and the second axis of the milling tool via an eccentric thereby moving the blank between the first machining position and a second machining position of the blank, the cutting surface of the milling tool being spaced from the cylindrical outer contour of the blank in the second machining position; and rotating the blank about the first axis such that the milling tool produces a plurality of straight edges of the bristles in cross-section as the blank intermittently moves between the first machining position and the second machining position thereby enclosing an angle of 180 degrees minus a predetermined angle with one another about the first axis by the plurality of straight edges.
 10. Device for producing a treatment element according to claim 9, characterized in that it has a first mounting for accommodating a blank and has a milling tool arranged parallel to the first mounting, in which case the blank can be fixed and rotated in the first mounting, in that the axis of the milling tool or of the blank runs via an eccentric, so that the radial distance of milling tool and blank varies, and in that, with the milling tool, by rotation about its axis, essentially straight cut edges of the bristle tips of the blank can be gradually produced in cross section until the treatment element has been produced with sections, adjacent to one another in cross section, of straight cut edges.
 11. A method for producing a treatment element for cleaning dental interstices, said method comprising the steps of: fixing a blank at a first rotational position about a first axis, the blank having a shaft and bristles of substantially equal length extending from the shaft; locating a milling tool adjacent the treatment element such that an outer cutting surface of the milling tool is in contact with the bristles; rotating the milling tool about a second axis parallel to the first axis thereby milling a first concave edge of bristles in cross-section from the blank; locating the blank away from the milling tool such that the outer cutting surface of the milling tool is not in contact with the bristles; rotating the blank about the first axis to a second rotational position thereby milling a second concave edge of bristles in cross-section from the blank; and forming other concave edges of bristles in cross-section on other sides of the blank by intermittently moving the blank to a position in contact with the bristles and a position not in contact with the bristles and intermittently rotating the blank to a plurality of rotational positions thereby forming a substantially polygon cross-section of the blank.
 12. (canceled)
 13. The method as defined in claim 1 further including the step of varying the distance between the first axis and the second axis via an eccentric.
 14. Device for producing a treatment element (1) for an appliance for cleaning dental interstices, which treatment element (1) can be mounted on such an appliance and comprises a shaft (2) from which bristles (3, 13, 23, 63) project radially, which treatment element (1) is a brush head having an essentially polygonal shape in cross section, said device comprising a rotatable mounting in which a blank having bristles of essentially the same length projecting from the shaft is fixed, a milling tool adjacent the rotatable mounting rotatable about an axis which runs parallel to the rotatable mounting, said mounting locating the blank in a first position with the axis of the milling tool arranged at a distance from the blank, and the milling tool producing essentially a first straight milled edge in cross section in the blank.
 15. A device as set forth in claim 14, wherein said rotatable mounting is rotationally indexed by predetermined angles by movement and in that, with the milling tool, initially and after each rotation, by rotation about its axis, an essentially straight cut edge of the bristle tips of the blank can be produced in cross section until the treatment element has been produced with sections, adjacent to one another in cross section, of straight cut edges.
 16. A device as defined in claim 14, wherein the radial of the milling tool and blank varies due to an eccentric. 